The DASP of the present invention are useful in serums, creams and lotions, lipsticks and other personal care products, either oil based or emulsions.
The products lower the surface tension of the oil phases to which they are added and despite their oil solubility, rather than silicone solubility, offer silicone feel and aesthetics to personal care formulations. Key to this performance is the presence of the alkyl group that provides solubility in the oil phase (by oil phase is meant a material insoluble in both silicone fluid and water).
Silicone fluids offer exceptionally low surface tension, in the area of 20 dynes/cm, but are insoluble in oils (both hydrocarbon and ester). Oils have a surface tension of around 30 dynes/cm and have a greasy feel. The compounds of the present invention when added to cosmetic oils lower the surface tension and provide outstanding skin feel, transfer resistance to lipsticks and conditioning effects to the hair and skin.
Another application of the compounds of the present invention is to reduce or eliminate syneresis in stick products. Lipsticks contain many water insoluble materials, including esters, hydrocarbons and silicone. Since silicone is insoluble in these systems, they bleed to the surface and cause sweating or syneresis, which is highly undesirable to the consumer. Incorporation of between 0.1 and 10% of the compounds of the present invention eliminate this problem.
Additionally, when added to pigmented products, these materials have an ability to coat the pigment and minimize the deposit of the pigments on glass, making the highly desirable transfer resistant lipstick without the need for expensive resins.
Additionally, the ability to lower surface tension of the conditioner applied to the skin that has a surface tension below 30 dynes/cm has been elusive since organic materials from which they are based have this value as the lower limit of surface tension achievable. Lower surface tension makes for better lubrication, and slip, resulting in improved skin feel.
Lower surface tension can only be achieved by using dimethyl silicones (also known as silicone fluids), but these polymers are not soluble in oils and have not been used. The present invention relates to including two very key groups on the silicone polymer, the first an alkyl group, improving the solubility of the silicone in oil, and also a very limited crosslink density that despite clarity in the oil results in the lowest free energy of the oil to be when the silicone polymer is pushed to the oil skin interface, where it surprisingly lowers surface tension.
The use of the compounds of the present invention, which have been found to be patentable, have not been used as conditioners in personal care applications.